Automatic safety valve for fuel burners



Sept. 29, 1953 w. A. RAY 2,653,522

AUTOMATIC SAFETY VALVE) FOR FUEL BURNERS Filedoct. 18, 1948 5 Sheets-Sheet 1 w/u/nm n. em

INVEl/TOIQ Sgpt. 29, 1953 W. A. RAY

AUTOMATIC SAFETY VALVE FOR FUEL Filed Oct. 18, 1948 BURNERS 5 Sheets-Sheet 2 92 so 86 [-18 n2 1 9|: ,IIOI 87 ac I IO 7 lo I02 9 H Y II 59 i so CHILL/HM fi. V

INVENTOQ HTTDBNEV Sept. 29, 1953 w. A. RAY 2,653,622

AUTOMATIC SAFETY VALVE FOR FUEL BURNERS Filed Oct. 1a, 1948 5 Sheets-Sheet s (Ma/4M, #7. 245,

- wvewme MMZW Sept. 29, 1953 w. A. RAY 2,653,622

AUTOMATIC SAFETY VALVE FOR FUEL BURNERS Filed Oct. 18, 1948 s Sheets-Sheet 4 76 W lll A 74 n 40mm! ,0. aw, INVENmQ arroQA/EV p 1953 w. A. RAY 2,65i3, a22

AUTOMATIC SAFETY VALVE FOR FUEL BURNERS Filed Oct. 18, 1948 5 sheets-sheet 5 M/l/ENW brmeua Patented Sept. 29, 1953 PU i yawn QB BS WilliamA. Ray,North Hollywood, Cal iL, 'asslgnor 'ito General qontrbl's (30.,

tornia mi iefidno ehe 18, 2a sewiall? a c aims (01. sm-cs) 1 This invention relateslto valves tor thecontrol of the flow of fuel to burners; and more par.-

ticularly to automatic safety valvesthatprevent flow of fuel to the of the pilot flame.

It has been commonin' the pastto p rovide a shut-off valve controlling the ,floyv of fuel so thait the valve is held open while a pilot flame is in existence. For example, this may be done by providing a mechanical structure, such as abimetallic element that is positioned to be afieeted by the pilot flame, or by the aid of anyother form of heat responsivedevice'.such'as a vaporizable or expandible fluid. Anotherlformincludesa thermocouple or thermopilethat has ahot junction heated by the pilot flame andzthat provides sufficient electric. power for an electromagnet'that can hold an armaturejin attracted position'. Ifhe armature is mechanically connected to a valve closure, which is heldlofif its seat when the a'rmature is in attracted position. HoweverQwhenthe pilot flame is extinguished, the armature moves away from th electromagnet.and theclosure is active to interrupt the flow of @fliel to thefmaih burner.

One of the problemsencountere d with sucha system is that of reestablishing the; pilot flame a safe manner. Although the power-available from the electromagnetis ampleyto .holdlt'he armature in attracted .position, yet it isincapable of attracting thearmture'tp thattposp tion. Accordingly, it is necessary .manuallyfto move th armature (and iteconnctedvalve'closure) to this attracted position,andtolighQthe pilot while the armature is thusheld, anduntil the pilot flame is established.

Such a manipulationuobviously perm'itsflQW of fuel to the main burner durin this resetting operation, and there is a n attendant danger [of explosion at the burner hecau'sefof thef copidus flowoiunignitedfu y In order to overcome. these difficulties arrangements have been proposed. to make it possible to ignite the pilot flame and'to lift thear'matHreiO attracted position without passing suegb the main burner. arrangemcnts of this bu e th T p 51 1? character are complex, andhave.otherise ou q i advantages. 7

It is one of the object's .of l this'invention to make it possible to perform theresett' jg eratiqn in a safe manner and withoutrequirin nually to place the armature inattractedlpos on.

In order to; accomplishr -these re ults', use' is made of a main rotary iplug valvet n a d it the safety shut-off valve, that may be operated ree erto interrupt flow of Iuel and that then autoinaticallyserves to .QDnQthe safety valve and to gcaliseithe' pilot name 'to maintain the valve in open position. either by the a ,o a erm coup e .or Lbyflafbiinetalligc s ructur o t iken. f erati t valve ,t los 10 e su 'ply'of'fuel',"'tlie' j s is soflqbnditioned that ignition of in p11 serves to latch the safety v a1ve;in1opei1 libsitiohflbut releases the safety .valve closure'whentheIpil t jflameisextinguished. All thisis' acc ,pli'she' itliout 'req'uiringmanfiaioperationo the arniature;

. t accordingly another v object of this inven- .tioh to provide"; cIifaIiical la'tch for holding I "pbsitiofi'when' the pilot I I I p c q Thislatchingifunction is jautdmaticgane' be acc mplished by any r gaipluiialitfbf H vi gthatirespond to the exgistencldf'th elpildt invention assess s many other advantages andhas'otli objectsjvvhich may be made friiore "c'larly'appar "team a" consideration of a term in yvhichit maybe embodied. This form is shown iiri' the drawings .accompanying and i tormifig part of thep r sent specification. It .vvill n yv-beLQescribed in detail; for the'purpose of illustrating the general principles of the invention but it. is to be; understood 7 that such detailed descriptiongis notto betakenin a'limiting sense,,singe the scope pf the invention is best .defin d-b heapr ededsla m 2 Re er n t hedrawm F e i e' is v rt c section w o th valve nfiw mte ine li iave tmm-th v v in li closed. o iti -M-Fig. 2 is -.af.vi ew similarli ,Fig.. 1, but showing he va ve i op n osition;

F 1 is..a. t 9na1;. v ew tak nal n a lan o re pond n t lin 3: o i i 1;

1 '-.:.4;, an exnlqde'diipcrspective 'viewof part-s .pfithevalve mechanism;

Fig.5 isifasdetail sectionalview, taken along a plane correspor'1ding to. line 5 5 of Fig." 1';

Fig -6*is' a diagrammatic; sectional view, taken along a -"planefcorfzfes "hding to line 6-6 of "Fig. 1-, and mars es fthei'ivalv'i in man; closed 20 M x 7 is a; sectional 1 view, talgen along a plane .wname ieit 112 o Fi 1'. an rr spondingitoftlie closed oSltion ofjth e valveas i s rate i fF 1.6; j

3 to Fig. '7, but showing the valve positions corresponding to Figs. 8, and 12, respectively;

Fig. 14 is a diagrammatic representation of the valve as shown in use in connection with a main burner and pilot burner installation;

Fig. is a plan View of a bracket and its associated parts utilized with the valve.

As shown most clearly in Figs. 1, 2, 3 and 4, the valve includes a valve body I which may appropriately be made from cast metal; for example, the body I may be madeas a die casting.

The valve body I has at its opposite ends the internally threaded bosses 2 and 3 into which are threaded, respectively, the inlet conduit 4 and the outlet conduit 5. The conduit 4 is connected to any appropriate source of fluid fuel, such as a gaseous fuel. The conduit 5 extends, as shown most clearly in Fig. 14, to a main burner 6.

The upper portion of the valve body I is open,

and is shown as closed by a flexible, movable wall, such as the diaphragm I. This diaphragm I is sealed against the top of the valve body I by the aid of a cap or cover 8 having a peripheral flange 9. This peripheral flange 9 may be fastened in place by a plurality of screws I0 engaging the flange 9 and urging the diaphragm I against a gasket or packing ring II.

In order for the fuel to pass through the valve, a plug valve, as well as a safety valve, must be open. The operating parts of both of these valves are accommodated in, and are supported by, the valve body I.

Thus, the inlet 2 communicates with a chamber I2 (see, particularly, Figs. 1 and 3). In the right-hand part of the body I, a plug valve structure is accommodated. A downwardly tapered seat I3 is provided by a sleeve member I4. This sleeve member may be cast into an appropriate opening formed in the casing I and extending upwardly to the chamber I2 and downwardly to the exterior of the casing. The right-hand wall of the casing I, as well as a wall I5, serves to define the opening in which the sleeve I4 is accommodated. An inlet port I6 is provided through the wall I5 and sleeve I4, and a similar outlet port I1 is provided in communication with the outlet conduit 5.

The port I6 opens into the chamber I2 and is controlled by a safety valve structure. In

order to provide a seat for the safety valve closure, the wall I5 carries a tapered valve seat I8. This valve seat is adapted to be engaged by a yielding valve closure disc I9, made of rubber or the like. This valve closure disc is in contact with a rigid metal disc carrying a retaining ear 2I. A washer 22 is mounted over the ear 2|, and serves as a backing for the closure structure. In order to hold the closure I9, disc 20, and washer 22 in place, a ring 23 is provided, the right-hand flange of which is turned inwardly to provide an abutment for the yielding closure member IS. A leaf spring 34, through which the ear 2I passes, serves to urge the elements I9, 20, and 22 against the inwardly directed flange of ring 23. The yielding closure disc I9, being made of rubber, or the like, readily accommodates itself against the seat 23.

The ear 2| is pivotally mounted, as by the aid of the pin 24, upon a lever 25. The configuration of this lever is shown to best advantage at the top portion of Fig. 4. The lever is provided with a wide arm 26 having depending side flanges 21. By the aid of these side flanges lever may be pivotallymounted upon a pin 21' (see, also, Fig.

3). This pin 21' is mounted on a stationary axis, and is supported by the aid of the body I. For this purpose there is provided a bracket member 28 (see, particularly, Figs. 1, 4 and 15). The bracket member 28 is provided with ears 23 and 30 for the accommodation of the fastening screws 3%. These fastening screws pass into the integrally formed bosses above the wall I5. Vertical ears are provided on the bracket 28 for the accommodation of pivot pin 21, the ends of which may be flattened.

Provisions are made to bias the safety valve closure member to the closed position of Fig. 1. For this purpose use is made of a compression spring 36. The upper end of this spring 36 engages the edge of a cup 31. The interior of this cup engages the downwardly extending flange 38 of lever 25. "Accordingly, the compression spring 36 urges the lever 25 in a counter-clockwise direction.

The lower end of the spring 36 rests upon a cup 39 which is formed integrally with the bracket 28 (Fig. 15).

The plug valve is controlled by a rotary plug closure 40. In the closed position of l and '7, the port 4i, through the plug ill, is transverse to the port I! and, therefore, no fuel can flow through the outlet port II. This port M, however, is in alignment with the port 42, which coinmunicates with a conduit 43 leading to the pilot burner 44 (Fig. 14). A sawcut or slot 45 is provided in the plug transverse to the port 4|. In this way, although flow of fuel to the outlet port I! may be interrupted, it is possible to pass fuel to the pilot flame when the safety valve closure structure is open. This is indicated diagrammatically in Fig. 9, in which the closure It is shown lifted from its seat. Fuel can then pass from the inlet 2 into the chamber I2 and port It through the slot and to the port 49;.

The plug M] is arranged to be manually controlled by the aid of a handle structure arranged below the body I. This handle structure includes a handle proper 43 that is attached, as by a screw 4'1, to a valve actuator 43. This valve actuator has a projection 49. This projection is accommodated within a slot 50 formed in the extension 5i of the plug 48 (Fig. 4), and. has a slight play therein.

Accordingly, when the handle is manipu- :lated, the plug 43 is moved correspondingly after the lost motion between the projection :59 and the slot 58 is taken up.

The mounting of the handle structure is shown to best advantage in Figs. 1, 2, and 3. An outer ball race 52 serves to confine the balls 53 against the shoulder formed by the projection on the sleeve I4. A retainer ring 55 is dis the balls 53. The ball race 5?. is brs otherwise attache-:1, to a hollow eylindi member 56. This skirt member 5'3 has cally opposite openings 5'! through which the transverse arm 53 of member 48 extends. This arm 58 also projects into the recesses formed at diametrally opposite points in a cover member 66, thus positively coupling the actuator 58 to the member 68. Thi cover member extends over the arm 58. It has an inwardly depressed portion 6| through which the screw 41' passes. In this Way the screw 41 firmly holds the actuating member 48 to the cover member and to the handle 46. Accordingly, the handle 4'5, actuator 68, cover member 53, and skirt 56 are all mechanically and firmly connected together to move angularly as a unit.

address In order to hbld the outer race-member in position so as to provide a rolling bearing for the handle structure, with'itsassociated skirt 56, use is made of a resilient, split ring 62* that engages a shoulder formed on the projection- 54. Interposed between this split ring 52 and the outer race 52 is a washer 63.

Since the outer ring 52 is held firmly to the skirt 56 by brazing, or the like; and since the bar 58 serves to clamp the skirt 53 to thecover member 66 and handle 46; it is obvious that rtation of the handle member 46=i-s guided by'th'e ball bearing structure; and this rotation can be effective to move the plug closure member 40in the desired angular positions. I

The arrangement is such that movement of the plug closure to the closed position of Fig. 9 serves to open the safety valve closure,- as shown most clearly in Fig. 8. In this position the projection 49 has been moved in a counter-clockwise direction to take up the play between slot 59 and the projection 49. In this position the safety valve closure is lifted. How this is accomplished will now be described.

The lever 25, whichserves to support the valve closure i9, is provided with an integral transverse arm 64 (see also Fig. 4 When this arm is urged upwardly, the lever 25" is moved in a counterclockwise direction about its pivot. This movement is effected by the aid of a push rod (Figs. 3 and 4). This push rod 65 is further guided in the aperture 56 formed in the ear 35 of bracket 28 (Fig. This push rod- 65 is urged downwardly to inactive position by a compression spring 61. The upper end of the spring engages the lower surfaceofthe ear 30. Its lower end engages a washer 68. This washer 68 is mounted upon the reduced upper end of the push rod 65 and is slidable within the cylindrical recess es in the body I. A yielding gasket or packing washer i0 is shown as disposed in the bottom of this recess 69. Furthermore, one or more grooves i! may be provided around the rod 55 for the accommodation of an appropriate lubri cant.

The ears 29 and 33, as shown most clearly in Fig. 15, also serve as an abutment for the heavy compression spring l2 that serves to urge the plug Gil into firm contact with its seat 1-3; The lower end of the spring i2 is appropriately accommodated within a recess !3 in the top of plug 40.

Movement of the push rod 65 against the-force of spring El is accomplished by the aid of a crank I l (Figs. 3 and 4). This crank 14 is pivotally mounted in a slot 15 provided in the lower portion of the casing l. Its inner arm engages the bottom of the recess 15 in order to limit clockwise rotation of the crank. The operating arm is in contact with the lower end of the push rod 65. The crank i may be urged in a counterclockwise direction by turning the handle 46. For this purpose an actuator 16, formed integrally with the outer race 52 (Fig. 1) is'utiliz'ed'. This actuator l6 projects through a slot formed in the upper edge of the skirt 56. V H I I When the projection 49' of member 48 is rotated to the position of Fig. 8,- the crank 14 is actuated and the safety valve closure movedto the position of Fig. 2. In this position the plug-40 interrupts the flow of fuel to the outlet I1, thereby preventing fiow of fuel to the main burner 6. However, fuel is now supplied to the pilot burner through ports I6, 45, 4| and 42. The handle 46 must be held in this position in order to compress the spring t7. As soon as the handle-isreleased,

the projection 49 returns to the positiofi'ofl 'ig; 6 under the influence of spring 6 1'; and,;uhiess the safety valve closure is otherwise held in" open position, this safety val-veclosure'also closes:

In order tohold the-safety valve-closure inopen position, it is necessary that the pilot burner 44 be ignited. This is accomplished while the-harrdle 46 holds the valve open, as shown in Figs. 8 and 9. Although other flame or heat responsive devicescan be used, in this instance a ther'nio electric system is utilized. Within thepilot flame 11 there is disposed the hot junction of la; thermocouple 18 (Fig. 14). When the'flam'e 11 is-in existence, electrical energy is generated which serves to operate an electromagnet'structure 1 9. This electromagnet structure in turnserves', when energized, to holder latch the lever 25 in the open position of Fig. 2.

The electromagnet' structure 19is conveniently placed within the casing or cover 8 above the diaphragm 1. It includes a U-shaped core- 80. This core 80, as shown most clearly in Figs-1 and 3', is attached to a bracket 8 l as by the screws. This bracket 8| has oppositely directed ears 8-3 which overlie the ends of posts 84. These posts are appropriately attachedas byweldingto the top of the cover member 8. Screws hold this bracket firmly in place. In thisway the electromagnet structure is supported within the cover or casing 8.

Upon the lower leg orcore 80 is mounted the coil 86, which is supplied with electrical energy from the thermocouple 18; Binding posts- H2 mounted on the left hand side of cap S ma'y be used to provide terminals for coil 86. The end of the lower leg of core 80 is provided with a reduced cylindrical portion 81 upon which a pole piece 88 is mounted. I v

Interposed between the bracket 81 and the upper leg of core 80 is a thin plate89' (Figs. 1, 2 and 5). This plate extends to the left and has arms Bil. A light armature 9'! has slots in" its opposite edges in which the arms 90 are engaged. In this way the armature is prevented from moving upwardly or downwardly. The armature 91 is pivoted on the knife edge 92 formed at the end of the upper arm of the core 80. The armature 91 is urged to the unattracted position of Fig. l by the aid of a light compression spring 93. This compression spring 93 has an end projecting into an aperture of an ear 94-. This car 94 is formed integrally with the bracket 8|. It also has a downwardly extending portion'95 serving to limit the movement of the armature 9| away from the pole piece 88. The right-hand end or the spring 93 passes through an aperture in the upper end of the armature 9|.

When the coil 86 isenergized by electrical energy derived from the thermocouple 18, it is attracted to the position shown in Fig. 2. The atmature 9! is purposely made light enough and is placed close enough to the pole piece 88 to complete this movement of the armature, although the thermocouple 18 provides very limited power.

The attraction of the armature 91 to the position of Fig. 2 serves to latch the lever 25 in the open position. For this purpose a latch structure is provided that is moved by movement of the lever 25 to the open position.

Thus, mounted upon the upper side of thdiaphragm 1 is an arm 96. This arm96 is attached to the lever 25 by the aid or'sc'r'ews's These screws 9'! pass through theidiaphragm "land are threaded into the tapped holes in the lever 25.

A washer 98 may be interposed between the member 96 and the diaphragm I.

When the arm 25 is moved in a clockwise direction to the open position of Fig. 2, the member 96 is likewise moved. The member 96 serves to move a latch member 99 (Figs. 1, 2 and 3). This latch member 99 is pivoted at its righthand end by the aid of a pin I00, passing through the downwardly extending arms IOI of bracket III. The ends of this pin may be flattened to limit its axial movement. The left hand end of the latch member 99 carries a latch projection I02. This latch projection I02 extends toward the right, and is provided with an upright projection I03. The left hand end of member 96 passes through an aperture in this projection.

In this way, when the lever 25 is moved to the open position by the operation of push rod 65, the member 96 serves to lift the latch member to the position of Fig. 2. Now, when the electromagnet I9 is energized, the armature 9| moves to the position of 2, and the left hand end of the latch projection I02 is engaged within the aperture I04 provided in latching member 9I.

This mechanical latching of the safety valve in open position is automatically effected while holding the handle 46 in safety valve opening position (corresponding to Figs. 8 and 9). As soon as the pilot flame TI is established, the handle 46 may be released and the safety valve closure structure is maintained in open position.

Thereafter, the handle 43 can be turned to open the main valve. This is accomplished by movement of the handle to correspond to the position of Figs. 10 and 11. Here, the port 4| of plug 40 is aligned with the inlet port I6 and the outlet port I'I. Fuel to the pilot burner is maintained through slot 45.

Upon failure of the pilot flame IT, the armature 9I is urged to the unattracted position of Fig. 1. The latch projection I02 is released, and the safety valve is closed by the action of spring 36. Fuel flow is interrupted both to the main burner 6 and the pilot burner 44. The pilot light must then be reestablished in order to make it possible to permit the fuel to pass to the main burner 6.

It may be desirable at times to turn the plug closure 40 to a fully inactive position where flow of the pilot burner is interrupted even when the safety valve is open. In order to effect this, the handle is turned to cause the plug to assume the position of Figs. 12 and 13. Here, the projection 49 of the handle structure has moved to its extreme position, and the port M is out of communication with the inlet port IS. The slot 45 is now no longer in a position to supply fuel to the pilot burner port 42.

The extent of movement of the plug between the positions of Figs. 7 and 13 is limited by the aid of stops. Thus, the projection 54 of sleeve I4 is provided with a stop abutment I05. This stop is shown diagrammatically in Figs. 6, 8, 10, and 12. The actuator 48 is provided with corresponding stops I06 and I91. In the extreme position of Fig. 8, where the actuator 41 is moved to open the safety valve structure, the stop I01 abuts the lower side of the stop I05. Now, as the actuator 48 is moved in a clockwise direction to the position of Fig. 12, the stop I06 contacts the upper side of the stop I05. The total movement of the projection 49, attached to the actuator 48, is slightly more than 180. However, due to the lost motion between pro- 8 jection 49 and slot 50, the plug 40 is moved through an angle slightly less than the angle of movement of actuator 48.

In operating the system it may be assumed that the plug 40 is in a position corresponding to Figs. 6 and '7. The safety valve is closed, and the passage of fuel both to the pilot burner and the main burner is interrupted.

The projection 49 is central with respect to the slot 50 due to the action of the push rod spring 61 on the crank 14, and thence to projection I6. Now, the handle structure can be turned so as to bring the projection 49 to the position of Fig. 8. In this position the crank I4 for actuating the push rod 05 is urged upwardly and the lever 25 is moved to the open position of Fig. 2. While holding the handle in this position, the pilot burner 44 may be ignited. In a short time, the armature 9I is attracted and the safety valve maintained in open position. The handle structure can then be moved in a clockwise direction, as viewed in Fig. 10, to move the plug 40 to the fully open position of Fig. 11. Fuel can then be supplied to the main burner 8, as well as to the pilot burner, and the handle left in this position.

In order that there be a definite feel or stop for the operator to move the plug no farther than to the open position of Fig. 11, use is made of a ball detent. This ball detent is shown most clearly in Fig. 3. It includes a ball I08 held in a socket member I99 that is disposed in the lower face of the body I. It is urged outwardly by a compression spring IIO, but it may be pushed out of the way against the spring.

When the plug 40 reaches the position of Figs. 10 and 11, the actuator arm I6 is moved to a position in contact with the ball I00. In order to move the plug 40 to the totally closed position of Fig. 12, this arm 76 must first depress the ball I03 against the spring IIO. Accordingly, the operator may move the plug 40 to the position of Fig. 10, and he will be warned by the excessive force required that to continue the movement of the plug would serve to bring the mechanism to the shut-down position of Figs. 12 and 13.

The main valve structure including the plug 40 is thus incapable of passing fuel to the main burner 6 unless the pilot is first established.

Control of the main burner 5 can be further accomplished by the aid of the electromagnetically operated valve I40 interposed in conduit 5. This valve opens in response to a conditionresponsive device, or limiting switch such as the thermostat III. Thus, although the plug valve may be open and the pilot established, the main burner 6 is ignited only when the valve I40 opens in response to the operation of device III.

The inventor claims:

1. In a fluid control system: a valve body providing a plug valve seat and having inlet and outlet ports opening in said seat, as well as a chamber communicating with one of said ports; a rotary plug in said seat; an operator for the plug; a safety valve closure structure in the chamber for controlling the said one of said ports and biased to closed position, said safety valve closure structure including a pivotally mounted member and a closure carried by the member; a flexible wall defining said chamber and attached to the member; an electromagnet structure supported externally of said Wall and having an armature that is moved to attracted position only in response to energization of said electromagnet;

zeta-e22 a latching member attached to the pivotally mounted member externally of the wall for movement along with said safety valve closure structure"; means responsive to a rotary movement of the operator only while the plug valve remains closed, to open the safety valve closure; said armature having a part thereof when said safety valve closure is in open position for engaging the latching member to hold the safety valve structure in open position when the armature is in attracted position; and means biasing said armature to disengaging position.

2. In a fluid control system: a valve body providing a plug valve seat and having inlet and outlet ports opening in said seat, as well as a chamber communicating with one of said ports; a rotary plug in said seat; an operator for the plug; a safety valve closure structure in the chamber for controlling the said one of said ports, and including a pivotally mounted member and a closure carried by the member; a flexible wall defining said chamber and attached to the member; an electromagnet structure supported externally of said wall and having an armature that is moved to attracted position only in response to energization of said electromagnet; means urging said safety valve closure structure to closed position; means responsive to a rotary movement of the operator only within an angle during which the plug valve is closed, for opening the safety valve closure against said urging means; a latching member attached to the pivotally mounted member externally of the wall for movement along with said safety valve closure structure; said armature having a part thereof effective when said safety valve closure is in open position for mechanically engaging the latching member to hold the safety valve structure in open position when the armature is in attracted position; and means for biasing said armature to releasing position.

3. In a safety valve structure: a valve body having a main inlet and outlet port, a main valve closure, as well as a chamber into which one of said ports opens; a movable safety valve closure in the chamber and biased to closed position; said safety valve closure cooperating with said one of said ports; a flexible wall defining said chamber; means dependent upon said main valve closure being in closed relationship with said outlet port for opening said safety valve closure; and means movable independently of said safety valve closure opening means for latching said safety valve in open position after said safety valve closure is moved to open position and arranged externally of the flexible wall., said latching means being biased to releasing position.

4. In a safety valve structure: a valve body having a main inlet and outlet port, a main valve closure as well as a chamber into which one of said ports opens; a movable safety valve closure in the chamber and biased to closed position; said safety valve closure cooperating with said one of said ports; a flexible wall defining said chamber; means dependent upon said main valve closure being in closed relationship with said outlet port for opening said safety valve closure; a latching member external of the chamber and attached to the Wall and the safety valve closure for movement with said safety valve closure; and electrically energized means having a part thereof movable independently of said safety valve 010- sure opening means for holding the latching member in position to maintain the safety valve to closure open after saidsafety valve closure is moved to open position, said electromagnetically energized means being biased to releasing position.

5 In a fluid control system: a main valve having a movable "closure; a safety valve in series with the main valve and havi-ng a mo'vable closure biased to closing position; means for operating the main valve closure to open and close the main valve; means for opening the safety valve closure in response to movement of the operating means and effective only during that part of the movement in which the main valve is closed; a first latching member carried by and movable with said safety valve closure; a movable second latch member engageable with said first latch member and biased to releasing position for holding said safety valve closure in open position; and condition responsive means for moving said second latch member to latching position independently of said safety valve closure opening means.

6. In a fluid control system: a main valve having a movable closure; a safety valve having a movable closure biased to closed position; said valves being in series arrangement; means for operating the main valve closure; means effective by movement of the operating means for opening the safety valve closure only during that part of the movement of the operating means in which the main valve is closed; a movable mechanical latching means carried by and movable along with said safety valve closure for holding said safety valve closure in open position; an electromagnet having an armature that is movable to attracted position only in response to energization of said electromagnet, said armature being movable independently of said operating means, means on said armature when in attracted position for latching said latching mechanism when said safety valve closure is in open position.

7. In a safety fuel valve structure: a main plug valve having a rotary plug closure; an operator for the closure; said main valve having inlet and outlet ports; the plug closure having an opening cooperating with said ports such that flow of fuel between the inlet and outlet ports is interrupted during a limited angle of movement of the operator; a safety valve having movable valve closure cooperating with one of said main valve ports and biased to closed position; means operated by movement of the operator only in said limited angle for moving the safety valve closure to open position; a latching means brought into latching position by movement of the safety valve closure to open position; and an electromagnet having an armature movable to attracted position only in response to energization of the electromagnet, and biased toward unattracted position; said armature being movable independently of said safety valve closure opening means; said armature and the latching means having engaging parts for holding the safety valve closure open after said safety valve is moved to open position.

8. In a safety valve structure: a valve body having a main inlet and outlet port as well as a chamber into which one of said ports opens; a movable safety valve closure in the chamber and biased to closed position; a flexible wall defining said chamber; a mechanical latch member carried exteriorly of the wall and attached to and movable along with the safety valve closure; and an electromagnet having an armature that is moved to attracted position only in response to the energization of the electromagnet and independently of said movable safety valve closure,

11' said armature having means engageable with said. latch member to hold said safety valve open, said armature being biased to unattracted position.

WILLIAM A. RAY.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Brunk Sept. 11, 1917 10 Number Number Number 

